Presser-bar-clamping mechanism for sewing-machines.



I No. 689,375. PatentewDec. l7, I90l.

R. e. WOODWARD.

PRESSER BAR CLAMPING MECHANISMFOR SEWING MACHINES.

(Application filed Mar. 29, 1899.)

(No Model.)

1/ r. U 3 5 h UNITED STATES PATENT Fries.

RUSSEL G. WOODWVARD, OF WAUKEGAN, ILLINOIS, ASSIGNOR TO THE UNION SPECIAL SEWING MACHINE COMPANY, OF CHICAGO, ILLINOIS, A CORPO- RATION OF ILLINOIS.

PRESSER-BAR-CLAMPING MECHANISM FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 689,375, dated December 17, 1901- Applioation filed March 29, 1899. Serial No. 710,990. (No model.) I

To all whom it may concern:

Be it known that I, RUssEL G. W001)- WARD, a citizen of the United States, residing at Waukegan, in the county of Lake, State of Illinois, have invented certain new and useful Improvements in Presser-Bar-Clamping Mechanism for Sewing-Machines, of which the following is a description, reference being had to the accompanying drawings and to the letters and figures of reference marked thereon.

The present invention relates to an' improvement in sewing-machines, its object being to provide an automatically-operated device timed to grasp the presser-bar to hold the same from vertical movement while the needles are drawing out of the goods, thus permitting their ready withdrawal, but preventing them from displacing the fabric, but so arranged as to release the bar and restore it to its normal spring-pressure while the feed is taking place.

It has been found in practice where the presser-foot is operated under the usual strong spring -pressure of its supporting-bar, and particularly where a number of thicknesses of material, such as leather, are to be sewed, when the feed comes up to take the work to move it forward the latter will be clamped so tightly that instead of moving forward the teeth of the feed-dog will dig into the fabric, this being particularly the case when in the sewing operation a seam is crossed. If to avoid this objection the presser-har spring is lightened, then the pressure is not great enough to strip the goods from the needles as the latter rise, but on the contrary the friction of the needles in the goods will draw up the presser-foot and the goods, thus displacing the latter. In the use of my invention, however, a minimum amount of pressure on the presser-bar may be utilized, so long as it is sufficient to lightly clamp the goods to hold them properly and the feed will move the goods along easily,while at the same time it is necessary to clamp them strongly while being stripped from the needles as the latter rise,and by my arrangement the presser bar is clamped immovably.

To this end, therefore, the invention consists in the matters hereinafterdescrihed, and referred to in the appended claims.

In the accompanyingd rawings, which illustrate the invention, Figure l is a side elevation of so much of a sewing-machine as is necessary to a complete understanding of my invention. Fig. 2 is an end perspective view of the same. Fig. 3 is a detail view of the presser-bar-clamping jaws.

In the drawings the invention is shown as applied to a Union Special cylinder vamper 6o sewing-machine, as covered, for example, by patent granted L. Onderdonk October 8, 1895, No. 547,675; but it will be understood that in its use the invention is not so limited, as it may be applied to any machine. The standard of the machine is shown at A, having the cylindrical bed or cloth plate B and the gooseneck or overhanging arm C, with the usual lugs having bearings for the needleloar D and presser-bar E, carrying the auxil- 7o iary presser-foot F, the bar being pressed downwardly by the flat spring G.

While I have referred to the part F as a presser-foot and the part E as a presserbar, it will be understood that said part F may be the ordinary needle-guide foot; but when I speak in the claims of the engagement and holding of the presser-bar in fixed position by means of the clamping mechanism hereinafter described it will be understood that I consider the claims broad enough to cover the invention whether applied to the needleguide foot-bar or to the presser-bar E, which carries the ordinary roller-presser foot F, which in practice has its bearing-periphery in a horizontal plane below the bearing-surface of the said needle-guide foot. As in the ordinary construction of the machines the presser-bars E and E are connected together so as to move as one, in the action of the camlever H and the spring G it will be understood that the clamping of one of said bars will hold them both in fixed position. It will be readily understood, however, that where the bars are not connected a separate clamp- 5 ing mechanism may be provided for each.

This of course would come within the scope of my invention, or the roller-foot may be dispensed with and the bar E instead of carrying a guide-foot may carry an ordinary presserfoot.

The driving-shaft S is provided with a spiral gear 1, which meshes with a similar gear 2 on the lower end of the vertical shaft 3, which shaft has its upper bearing in the gooseneck of the sewing-machine and projects therethrough, carrying on its upper end an eccentric 4, about which is clamped a head 5, having a socket 6. in which is secured one end of a pitman-rod 7. At the opposite end the pitman-rod 7 is fastened to the end of a block 8, sliding upon a guiding stud or screw 9, which passes through a slot 10 in the block into a lug or projection ll on the gooseneck of the machine. This block 8 has side lugs or projections 12, through which pass screw-bolts 13, provided on their lower ends with antifriction-rollers 14. v, Extending between these rollers are the two arms 15 of a pair of clamping tones or grips pivoted togethcr at 16 and formed at their outer ends with jaws 17 toembrace the upper end of the presser-bar E. A spring 18 between the arms 15 keeps the latter and the jaws 17 open. It will thus be seen that as the block 8 reciprocates the jaws 17 are alternately opened and closed to release or clamp the presser-bar E, and the movements are so timed that the clamping action takes place while the needles are moving up and the feed is down.

Various minor modifications and changes in the construction of this application may be made without departing from the spirit of my invention.

Having thus described my invention, what I claim, and desire to secure by Letters Pat- 1. The combination in asewing-m'achine, with the driving-shaft, of a foot adapted to bear upon the fabric to be sewed, and pivoted clam ping-jaws operatively connected with the driving-shaft and adapted to hold said normally pressed apart foot in fixed position while the needles are movingout of the fabric; substantially as described.

2. In a sewing-machine, the combination with a plurality of presser-bars, a presserfoot bearing on the Work, and an auxiliary presser-foot, and pivoted clamping-jaws for alternately holding said bars in fixed position and releasing the same, and means for operating the pivoted jaws; substantially as described.

3. In a sewing-machine, a driving-shaft, a shaft driven thereby and arranged at right angles thereto, a slidinghead on the machineframe, connections between the'same and the latter shaft for reciprocating it,pivoted clamping-jaws adapted to be opened and closed by the reciprocation of said sliding head, and a presser-bar adapted to be engaged and released by said pivoted clamping-jaws; substantially as described.

4. In a sewing-machine, a presser-bar, clamping-jaws engaging the same having rearwardly-extending arms, a block having projections between which the said arms extend, and means for reciprocating said block; substantially as described.

5. In a sewing-machine, the combination with a needle-bar carryingaplnralityof needles, of a main roller-presser, an auxiliary presser, with pivoted clamping-jaws for holding said roller and auxiliary presser in fixed position at a certain period during the sewing operation, and means for operating the pivoted jaws; substantially as described.

6. In a sewing-machine, adriving-shaft, an upright shaft driven thereby, an eccentric thereon, a pitman driven by said eccentric, and pivoted clamping-jaws adapted to engage the presser-bar, and operated by the pitman; substantially as described.

Ill-testimony whereof I affix my signature in presence of two Witnesses.

RUSSEL G. WOODWARD. Witnesses:

CHESTER McNEIL, JAMES R. TROWBRIDGE. 

